ES2984909T3 - Contention window size adjustment feedback - Google Patents

Abstract

Embodiments of the present disclosure relate to apparatus, methods, and computer-readable storage media for contention window size (CWS) adjustment feedback. The first device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the at least one device to receive at least one transport block from a second device in a predetermined bandwidth portion for a transmission from the second device to the first device, the at least one transport block transmitted in a set of subbands of the predetermined bandwidth portion; generate feedback based on a set of reception states of the at least one transport block in the set of subbands; and transmit the feedback to the second device such that the second device adjusts a contention window size (CWS) for further transmission from the second device to the first device. In this way, feedback corresponding to interference conditions with a given subband can be provided for CWS adjustment and signaling overhead is significantly reduced. (Automatic translation with Google Translate, no legal value)

Description

DESCRIPTION

Contention window size adjustment feedback

Field

Embodiments of the present disclosure relate generally to the field of telecommunications and in particular to methods, devices, apparatus, and computer-readable storage media for contention window size (CWS) adjustment feedback.

Background

Harmonious coexistence between Long Term Evolution with Licensed Assisted Access (LTE-LAA) and WIFI is a topic of research due to the deployment of LTE in the 5 GHz unlicensed spectrum. The listen-before-talk (LBT) scheme works as a requirement in unlicensed spectrum to ensure fairness between different radio access technologies. For unlicensed NR (nRu), TR 38.889 defines LBT with random backoff with a variable-sized contention window.

As is known, the LBT procedure is a mechanism by which a transmitting entity must apply a Channel Clear Assessment (CCA) check before using the channel and the CCA check time should depend on a random back-off and the contention window size. For the CWS adjustment procedure, R-U can at least consider Code Block Group (CBG) based HARQ ACK operation and wideband carrier (>20 MHz) operation in a portion of wideband bandwidth (BWP). In wideband BWP, there can be one Transport Block (TB) scheduled in multiple LBT sub-bands while the CWS must be adjusted based on the LBT sub-band. R1-1813994 “Feature Lead’s Summary on Channel Access Procedures” by Nokia et al., November 14, 2018, describes topics relevant to channel access procedures.

Summary

In general, illustrative embodiments of the present disclosure provide a contention window size (CWS) adjustment feedback solution. The invention is set forth in the appended set of claims.

Brief description of the drawings

The embodiments of the description are presented in the sense of examples and their advantages are explained in greater detail below, with reference to the accompanying drawings, where

Figure 1 shows an illustrative communication network where illustrative embodiments of the present disclosure may be implemented;

Figure 2 shows a schematic diagram illustrating a process for CWS adjustment feedback according to illustrative embodiments of the present disclosure;

Figure 3 shows a diagram of an example of a transport block transmitted on multiple subbands in accordance with some illustrative embodiments of the present disclosure;

Figure 4 shows a diagram of an example of a plurality of CBs transmitted in a subband according to some illustrative embodiments of the present disclosure;

Figure 5 shows a flow chart of an illustrative method 500 for CWS adjustment feedback according to some illustrative embodiments of the present disclosure;

Figure 6 shows a flow chart of an illustrative method 600 for CWS adjustment feedback according to some illustrative embodiments of the present disclosure;

Figure 7 shows a simplified block diagram of a device that is suitable for implementing illustrative embodiments of the present disclosure; and

Figure 8 shows a block diagram of an illustrative computer-readable medium according to some embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numbers represent the same or similar item.

Detailed description

The subject matter described herein will now be discussed with reference to several illustrative embodiments. It should be understood that these embodiments are discussed only for the purpose of enabling those skilled in the art to better understand, and thereby implement, the subject matter described herein, rather than to suggest any limitation on the scope of the subject matter.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments. As used herein, the singular forms “a,” “an,” “the,” and “the” are intended to include the plural forms unless the context clearly dictates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used herein, specify the presence of the disclosed features, constituent elements, steps, operations, elements, and/or components, but do not exclude the presence or addition of one or more other features, constituent elements, steps, operations, elements, components, and/or groups thereof.

It should also be noted that in some alternative implementations, the functions/actions shown may occur outside the order indicated in the figures. For example, two functions or acts shown in succession may actually be executed simultaneously or may sometimes be executed in the reverse order, depending on the functionality/actions involved.

As used herein, the term “communication network” refers to a network that follows any suitable communication standard, such as Long Term Evolution (LTE), LTE Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High Speed Packet Access (HSPA), and so on. Furthermore, communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocol, including, but not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, future fifth generation (5G) communication protocols, and/or any other protocols currently known or developed in the future.

Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future-type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the system mentioned above. For illustrative purposes, embodiments of the present disclosure will be described with reference to the 5G communication system.

The term “network device” as used herein includes, but is not limited to, a base station (BS), a gateway, a registration management entity, and other suitable device in a communication system. The term “base station” or “BS” represents a node B (NodeB or NB), an evolved node B (eNodeB or eNB), an N<r>NB (also referred to as a gNB), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a relay, a low power node such as a femto, a pico, and so on.

The term “terminal device” used herein includes, but is not limited to, “user equipment (UE)” and other suitable end device capable of communicating with the network device. By way of example, “terminal device” may refer to a terminal, a mobile terminal (MT), a subscriber station (SS), a portable subscriber station, a mobile station (MS), or an access terminal (AT).

The term “circuitry” used herein may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in analog-only and/or digital-only circuit sets) and

(b) combinations of physical circuits and software, such as (as applicable):

(i) a combination of analog and/or digital hardware circuit(s) with

software/firmware and

(i) any portion of a hardware processor or processors with software (including digital signal processor(s), software and memory(ies) that operate together to cause a device, such as a mobile phone or server, to perform various functions) and

(c) a hardware circuit(s) and/or processor(s), such as a microprocessor(s) or part of a microprocessor(s), that requires software (e.g., firmware) for its operation, but the software may not be present when it is not necessary for operation.”

This definition of circuitry applies to all uses of this term in this application, including in any claim. As a further example, as used in this application, the term circuitry also covers an implementation of only a physical circuit or processor (or multiple processors) or a portion of a physical circuit or processor and its accompanying software and/or firmware. For example, and if applicable to a particular claim element, the term circuitry also covers a baseband integrated circuit or processor integrated circuit for a mobile phone or a similar integrated circuit in a server, cellular network device, or other computing or network device.

1 shows an illustrative communication network 100 in which embodiments of the present disclosure may be implemented. The network 100 includes a second device 120 (hereinafter, may be referred to as network device 120) and first devices 110-1 and 110-2 (hereinafter, collectively referred to as first devices 110 or individually referred to as terminal device 110) served by the network device 120. The service area of the network device 120 is referred to as a cell 102. It should be understood that the number of network devices and terminal devices is for illustration purposes only without suggesting any limitation. The network 100 may include any suitable number of network devices and terminal devices adapted to implement embodiments of the present disclosure. Although not shown, it will be appreciated that one or more terminal devices may be in the cell 102 and served by the network device 120.

Communications in the network 100 may conform to any suitable standard including, but not limited to, Long Term Evolution (LTE), LTE Evolution, LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), and Global System for Mobile communications (GSM), and the like. Communications may also be performed in accordance with any generation of communication protocols currently known or developed in the future. Examples of the communication protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols.

As described above, the Listen Before Talk (LBT) procedure is a mechanism whereby a transmitting entity must apply a Clear Channel Assessment (CCA) check before using the channel and the CCA check time must depend on a random back-off and the contention window size. For the CWS adjustment procedure, NR-U may at least consider HARQ ACK operation and wideband carrier (>20 MHz) operation in a wideband bandwidth (BWP) portion.

In LTE-LAA, CWS are maintained and updated separately for each 20 MHz carrier. At least for one band where Wi-Fi-free operation cannot be guaranteed (e.g. by regulation), it is agreed that NR-U LBT can be performed in 20 MHz units. The simplest solution is that CWS maintenance is also performed separately in each 20 MHz sub-band. This is particularly the case for wideband (WB) operation with a primary LBT sub-band.

For efficient CWS adjustment in NR-U with wideband operation, CWS should be adjusted on a per LBT sub-band basis (per 20 MHz). However, a single data transport block (TB), comprising a certain number of code blocks (CB), may be transmitted/scheduled in multiple sub-bands. Therefore, a single HARQ ACK for a TB covering multiple LBT sub-bands is insufficient for CWS adjustment. Channel utilization/interference in different sub-bands of a BWP may be different. For example, there is interference resulting in failed decoding of some code block groups (CBG) in only one LBT sub-band, the HARQ ACK will be “NACK” for the entire TB and accordingly CWS will be incremented for all LBT sub-bands on which the TB is transmitted, which may cause unnecessary delays for channel access.

In addition to TB-based HARQ ACK feedback, NR can also support CBG-based HARQ ACK feedback, where separate HARQ ACKs can be provided for individual CBs or CBGs, i.e. parts of a TB. In principle, CBG-based HARQ ACK feedback could also assist CWS tuning in the case described above by providing finer granularity for HARQ ACK feedback.

However, this approach has certain drawbacks. For example, CB correlation in NR Rel-15 is performed frequency-first, resulting in a single CB typically spanning multiple 20 MHz subbands. This can essentially defeat the purpose of using CBG-based feedback to distinguish between interference situations in different subbands.

Furthermore, the granularity of CBG-based HARQ ACK feedback is unnecessarily fine (up to 8 CBGs) and CBs are approximately equally distributed among CBGs, which also contradicts the purpose of CWS tuning where it only focuses on 20 MHz granularity and CBs within an LBT subband. Setting 8 CBGs to better approximate LBT subband splitting will result in unnecessary signaling overhead. If CBG is configured, CBG-based feedback is applied for all transport blocks.

However, for CWS tuning, this introduces unnecessary overhead, as CWS tuning only depends on data received in the reference slot(s), which can typically be located at the start of a downlink (DL) or uplink (UL) burst. Other slots in the DL/UL burst may not be required to be considered in CWS maintenance, and therefore CBG-based HARQ ACK feedback is not needed for those slots either.

Therefore, the present disclosure proposes a new type of feedback that supports CWS tuning especially in a case where one or more TBs are mapped to at least two LBT subbands.

Figure 2 is a schematic diagram of a process 200 for a grant operation configured in accordance with illustrative embodiments of the present disclosure. For purposes of discussion, process 200 will be described with reference to Figure 1. Process 200 may involve terminal device 110 and network devices 120 as illustrated in Figure 1.

As shown in Figure 2, the network device 120 transmits at least one TB to the terminal device 110 at a predetermined BWP. The at least one transport block is transmitted on a set or subset of subbands falling within a predetermined bandwidth portion.

As mentioned above, the network device may allocate a predetermined BWP of the bandwidth for a DL transmission of the TB from the network device 120 to the terminal device 110, while the LBT may be performed in each 20 MHz sub-band. That is, the predetermined BWP may span far beyond the LBT sub-band range, i.e., 20 MHz. Therefore, the TB may be transmitted in a plurality of sub-bands in the predetermined BWP.

Figure 3 shows a diagram of an example of a TB transmitting on multiple subbands in accordance with some illustrative embodiments of the present disclosure.

As shown in Figure 3, there are two TBs 320 and 330 transmitted in the default BWP. For example, TB 320 including blocks 321, 322, 323, and 342 may be transmitted in subbands 311, 312, 313, and 314 of the default BWP, and each block may be transmitted in one subband. For example, block 321 is transmitted in subband 321. Figure 3 also shows another TB 330 including 331, 332, and 333 that is transmitted in the default BWP. Compared to TB 320, which is transmitted in all subbands of the default BWP, TB 330 is only transmitted in a subset of three subbands of the default BWP.

Returning to Figure 2, the terminal device 110 may receive the TB in the set of subbands and determine the reception state of at least one transport block for each subband of the set of subbands. That is, for the received TB, the terminal device 110 may determine a set of reception states of the transport block that includes the reception state for each subband in which the TB is transmitted.

For example, for the TB shown in Figure 3, the set of receive states may comprise the receive state of block 321 in subband 311, the receive state of block 322 in subband 312, the receive state of block 323 in subband 313, and the receive state of block 324 in subband 314.

As shown in Figure 2, based on the determined set of transport block reception states in the set of subbands, the terminal device 110 generates 220 a feedback. The feedback may indicate the transport block reception state for each subband.

In some illustrative embodiments, the terminal device 110 may generate a bit sequence and each bit may indicate whether reception of the transport block on one of the set of subbands is successful.

For example, for the TB shown in Figure 3, if blocks 321-323 are successfully received on subbands 311-313, respectively, and block 324 is not successfully received on subband 314, the bit sequence generated by the terminal device 110 may be represented as “1110”, where the “1” bit may represent “ACK” for TB reception and the “0” bit may represent “NACK” for TB reception.

The terminal device 110 may generate the feedback based on the bit sequence, which is generated based on the reception status of the transport block in each of the set of subbands.

For a TB transmitted on all subbands in the default BWP, the length of the TB may correspond to the number of subbands in the default BWP. That is, for example, there are 4 subbands in the default BWP and then the sequence may comprise 4 bits.

For a TB transmitted on only a portion of the subbands in the default BWP, the sequence may optionally reflect only the reception states of the subbands on which the TB is transmitted. For example, for TB 330 shown in Figure 3, if blocks 331 and 332 are successfully received on subbands 312 and 313, respectively, and block 333 is not successfully received on subband 314, the bit sequence generated by terminal device 110 may be represented as “110”.

Alternatively, a default value may be assigned for each subband in the default bandwidth portion where no TB is transmitted. In this case, the sequence may be generated based on the receive states and the default value. For example, if the default value is designated as “1”, the sequence for TB 330 may be “1110”, where the first “1” is a default value. Alternatively, the default value may also be designated as “0”.

In some illustrative embodiments, the terminal device 110 may determine a reference time interval, e.g., a reference slot 340 in the predetermined bandwidth portion for determining TB reception states. The reference slot may be a certain slot in the UL or DL burst. The UL/DL burst may reference a set of continuous resources for UL/DL transmission. For example, the reference slot may be the first or last slot in the UL or DL burst. In alternative embodiments, the slot may also be a mini-slot or a sub-slot. The indication of the reference slot may be obtained for the network device 120 from previous signaling.

As mentioned above, a TB may comprise a plurality of CBGs consisting of one or multiple CBs. In this given reference slot 340, the terminal device 110 may select one or more CBGs in at least one transport block in the reference slot. Figure 4 shows a diagram of an example of a plurality of CBs transmitted in a subband according to some illustrative embodiments of the present disclosure.

As shown in Figure 4, in sub-band 311, there are multiple CBGs (e.g., CBG 411) and each CBG may comprise multiple CBs (e.g., CB 431 is one of five CBGs in a CBG). In some embodiment, a CBG may also be only a single CB. It should be understood that one or more TBs may be transmitted in a sub-band within reference slots. In determining the interference status in a sub-band (e.g., sub-band 311), only CBGs or CBs in this sub-band may be considered. For example, as shown in Figure 4, the CBG 412 may be transmitted over 2 sub-bands, i.e., sub-bands 311 and 312. Therefore, the CBG 412 may not be taken into consideration for determining the reception state in sub-band 311. In some illustrative embodiments, in reference slot 340, the CBGs or CBs of a certain TB may be selected to determine the reception state in sub-band 311. Figure 4 also shows an embodiment, where the CBs are correlated in sub-band first, in frequency second, in time third, and the time direction is reversed between neighboring transmitted sub-bands.

The terminal device 110 may determine the reception status based on the successful reception rate of the CBGs in a sub-band or based on the successful reception rate of the CBs in a sub-band. The successful reception rate may indicate how many CBGs or CBs in this sub-band have been successfully received. If the terminal device 110 determines the successful reception rate of the CBGs in a sub-band or the successful reception rate of the CBs in a sub-band exceeds a threshold reception rate, the terminal device 110 may determine the successful reception of the transport block in this sub-band.

For example, if all of the CBs or CBGs in the reference slot 340 are “ACK”, the terminal device 110 may determine successful reception. Alternatively, if a certain percentage of the CBs or CBGs in the reference slot 340 are “ACK”, the terminal device 110 may determine successful reception. As an option, if at least one CB or CBG in the reference slot 340 is “ACK”, the terminal device 110 may determine successful reception.

Optionally, the terminal device 110 may also include more than one bit sequence as the feedback. For example, the terminal device 110 may generate a first bit sequence corresponding to the first TB in the reference slot and generate a second bit sequence corresponding to the second TB in the reference slot. Both the first and second bit sequences may be considered as the feedback.

Returning to Figure 2, the terminal device 110 transmits 230 the feedback to the network device 120.

In some illustrative embodiments, the terminal device 110 may transmit the feedback with a response for receipt of the TB from the terminal device 110 to the network device 120.

In some illustrative embodiments, the terminal device 110 reports the feedback to the network device along with HARQ ACK feedback corresponding to at least one TB or candidate TB in the reference slot, following the timing for HARQ that is indicated by a K1 value in the DL assignment scheduling the DL data transport block. Assuming that the terminal device 110 is aware of the reference slot, when the terminal device 110 is triggered to report HARQ ACK feedback for at least one TB or candidate TB in said slots, the terminal device 110 will also include the CWS adjustment feedback in the report.

In some illustrative embodiments, the terminal device 110 may transmit the feedback at the timing specified by the network device 120. The timing and the presence of CWS adjustment feedback may be indicated in the DL assignment that schedules the DL data into reference slots from the network device 120. For example, there may be, e.g., a 1-bit flag in the DL assignment to inform the terminal device 110 that for the given DL TB a CWS adjustment feedback should also be included in the UCI (in addition to the normal HARQ ACK feedback).

In some illustrative embodiments, the feedback is transmitted together with the HARQ ACK codebook associated with, e.g., the last transmitted transport block within the reference slots for the terminal device 110. That is, the CWS adjustment feedback is not reported with other HARQ ACK codebooks associated with previous TBs in the reference slots.

Now, returning to Figure 3, in some illustrative embodiments, for TBs 320 and 330 transmitted in reference slot 340, the CWS adjustment feedback is determined based on code blocks in TBs 320 and 330. After the terminal device 110 has determined the CWS adjustment feedback based on the aforementioned mechanism, it reports the CWS adjustment feedback along with the HARQ ACK feedback on resources in another slot, e.g., block 351.

In some illustrative embodiments, if the terminal device 110 determines the CWS adjustment feedback based only on the TB 320, the CWS adjustment feedback is multiplexed together with the HARQ ACK feedback for the TB 320. In this example, there is a clear one-to-one correlation between the timing of the CWS adjustment feedback and the timing of the corresponding HARQ ACK. For example, the CWS adjustment feedback may be reported together with the HARQ ACK at block 351.

In some illustrative embodiments, the CWS adjustment feedback is also determined based on code blocks in TBs 320 and 330. However, the CWS adjustment feedback may be multiplexed with only the HARQ ACK CB determined by DCI scheduling TB 330, in block 352. Alternatively, the CWS adjustment feedback could be multiplexed with both HARQ ACK feedbacks, i.e., blocks 351 and 352 at the expense of increased overhead.

As shown in Figure 2, after receiving feedback from the terminal device 110, the network device 120 adjusts 240 a CWS for further transmission from the second device to the first device based on the feedback.

In some illustrative embodiments, the network device 120 may determine the transport block reception states for each subband in the predetermined BWP. If the network device 120 determines a successful reception of the transport block in a subband, the network device 120 may reset the CWS for the subband. Otherwise, the network device 120 may increase the CWS for the subband.

In some illustrative embodiments, the network device 120 may obtain a bit sequence from the feedback to determine the reception status of the transport block on each of the subbands.

As mentioned above, a feedback may comprise more than one sequence. In this case, the bit of each sequence corresponding to the same subband may be taken into consideration to determine the reception status of the transport block in this subband.

In this way, feedback corresponding to interference conditions with a certain subband can be provided for CWS tuning and the signaling overhead is significantly reduced.

Further details of illustrative embodiments according to the present disclosure will now be given with reference to Figures 5 and 6.

Figure 5 shows a flowchart of an illustrative method 500 for a grant operation configured in accordance with some illustrative embodiments of the present disclosure. The method 500 may be implemented in the terminal device 110 shown in Figure 1. For purposes of discussion, the method 500 will be described with reference to Figure 1.

At 510, the terminal device 110 receives at least one transport block from a second device in a predetermined bandwidth portion for transmission from the network device 120 to the terminal device 110, the at least one transport block being transmitted in a set of subbands of the predetermined bandwidth portion.

At 520, the terminal device 110 generates feedback based on a set of reception states of the at least one transport block in the set of subbands.

In some illustrative embodiments, the terminal device 110 may determine at least one reference time slot in the predetermined bandwidth portion for transmission. The terminal device 110 may further determine whether the at least one transport block is received in the at least one reference time slot, and if the terminal device 110 determines a reception of the at least one transport block in the at least one reference time slot, the terminal device 110 may generate the feedback.

In some illustrative embodiments, the terminal device 110 may receive an indication of the at least one reference from the network device 120 and determine the at least one reference time interval based on the indication.

In some illustrative embodiments, the terminal device 110 may generate a bit sequence based on the reception states in the set of subbands, each bit indicating whether a reception of the at least one transport block in one of the set of subbands is successful. The terminal device 110 may further generate feedback based on the bit sequence.

In some illustrative embodiments, the terminal device 110 may assign default values for subbands in the predetermined bandwidth portion in which no transport block is transmitted and generate the bit sequence based on the reception states and the default values.

In some illustrative embodiments, the terminal device 110 may select one or more groups of code blocks in the at least one transport block of the at least one transport block transmitted in a same subband in at least one reference time slot and determine a successful reception rate of the selected groups of code blocks. If the terminal device 110 determines that the successful reception rate exceeds a threshold reception rate, the terminal device 110 may determine successful reception of the at least one transport block.

At 530, the terminal device 110 transmits the feedback to the second device such that the second device sets a CWS for further transmission from the network device 120 to the terminal device 110.

In some illustrative embodiments, the feedback is transmitted together with a response for receipt of the at least one transport block from the terminal device 110 to the network device 120. In some illustrative embodiments, the response comprises a hybrid auto-repeat request confirmation of the at least one transport block.

In some illustrative embodiments, the terminal device 110 may receive from the second device an indication of a timing configured for the feedback and transmit the feedback at the timing based on the indication. In some illustrative embodiments, the timing configured for the feedback is a timing for a hybrid auto-repeat request acknowledgement corresponding to the at least one transport block.

Figure 6 shows a flowchart of an illustrative method 600 for a grant operation configured in accordance with some illustrative embodiments of the present disclosure. The method 600 may be implemented in the network device 120 as shown in Figure 1. For purposes of discussion, the method 600 will be described with reference to Figure 1.

At 610, the network device 120 transmits at least one transport block to a terminal device 110 in a predetermined bandwidth portion for a transmission from the network device 120 to the terminal device 110, the at least one transport block being transmitted in a set of subbands of the predetermined bandwidth portion.

In some illustrative embodiments, the network device 120 may determine at least one reference time interval in the transmission. The network device 120 may also generate an indication of at least one reference time interval and transmit the indication to the terminal device 110.

At 620, the network device 120 receives feedback from the first device, the feedback generated based on a set of reception states of the at least one transport block in the set of subbands.

In some illustrative embodiments, the feedback is transmitted together with a response for receipt of the at least one transport block from the terminal device 110 to the network device 120. In some illustrative embodiments, the response comprises a hybrid auto-repeat request confirmation of the at least one transport block.

In some illustrative embodiments, network device 120 may transmit an indication of a timing configured for feedback to terminal device 110 and receive feedback on the timing based on the indication.

At 630, the network device 120 adjusts a CWS for further transmission from the network device 120 to the terminal device 110 based on the feedback.

In some illustrative embodiments, the network device 120 may determine the set of reception states of the at least one transport block in the set of subbands from the feedback. If the network device 120 determines a successful reception of at least one transport block in a first subband of the set of subbands, the network device 120 may reset the CWS for the first subband. If the network device 120 determines an unsuccessful reception of at least one transport block in a second subband of the set of subbands, the network device 120 may increase the CWS for the second subband.

In some illustrative embodiments, the network device 120 may obtain a bit sequence from the feedback, each bit indicating whether a reception of at least one transport block in one of the set of subbands is successful, and determine the set of reception states based on each bit of the bit sequence.

In some illustrative embodiments, an apparatus capable of carrying out the method 500 (e.g., implemented in the terminal device 110) may comprise means for performing the respective steps of the method 500. The means may be implemented in any suitable manner. For example, the means may be implemented in circuitry or in a software module.

In some illustrative embodiments, the apparatus comprises means for receiving at least one transport block from a second device in a predetermined bandwidth portion for a transmission from the second device to the first device, transmitted the at least one transport block in a set of subbands of the predetermined bandwidth portion; means for generating feedback based on a set of reception states of the at least one transport block in the set of subbands; and means for transmitting the feedback to the second device such that the second device adjusts a contention window size (CWS) for further transmission from the second device to the first device.

In some illustrative embodiments, an apparatus capable of performing method 600 (e.g., implemented in network device 120) may comprise means for performing respective steps of method 600. The means may be implemented in any suitable manner. For example, the means may be implemented in circuitry or in a software module.

In some illustrative embodiments, the apparatus comprises means for transmitting at least one transport block to a first device in a predetermined bandwidth portion for a transmission from the second device to the first device, the at least one transport block transmitted in a set of subbands of the predetermined bandwidth portion; means for receiving feedback from the first device, the feedback generated based on a set of reception states of the at least one transport block in the set of subbands; and means for adjusting a contention window size (CWS) for a further transmission from the second device to the first device based on the feedback.

Figure 7 is a simplified block diagram of a device 700 that is suitable for implementing embodiments of the present disclosure. The device 700 may be provided to implement the communication device, for example, the terminal device 110 as shown in Figure 1. As shown, the device 700 includes one or more processors 710, one or more memories 740 coupled to the processor 710, and one or more transmitters and/or receivers (TX/RX) 740 coupled to the processor 710.

The TX/RX 740 is for two-way communications. The TX/RX 740 has at least one antenna to facilitate communication. The communication interface can represent any interface that is necessary for communication with other network elements.

The processor 710 may be of any type suitable for the local technical network, and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), and processors based on a multi-core processor architecture, as non-limiting examples. The device 700 may have multiple processors, such as an application-specific integrated circuit chip that is time-dependent on a clock that synchronizes the main processor.

Memory 720 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, a read-only memory (ROM) 724, an electrically programmable read-only memory (EPROM), flash memory, hard disk, compact disk (CD), digital video disk (DVD), and other magnetic storage and/or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 722 and other volatile memories that will not last for the duration of a power off.

A computer program 730 includes computer-executable instructions that are executed by the associated processor 710. The program 730 may be stored in the ROM 1020. The processor 710 may perform any suitable actions and processing by loading the program 730 into the RAM 720.

Embodiments of the present disclosure may be implemented by program 730 such that device 700 may perform any process of the disclosure as described with reference to Figures 2 through 6. Embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some embodiments, the program 730 may be tangibly contained on a computer-readable medium that may be included in the device 700 (such as in memory 720) or other storage devices that may be accessed by the device 700. The device 700 may load the program 730 from the computer-readable medium into RAM 722 for execution. The computer-readable medium may include any type of tangible non-volatile storage, such as a ROM, EPROM, flash memory, hard drive, CD, DVD, and the like. Figure 8 shows an example of the computer-readable medium 800 in the form of a CD or DVD. The computer-readable medium has the program 730 stored thereon.

Generally, various embodiments of the disclosure may be implemented in hardware or in specialized circuitry, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other graphical representation, it is to be understood that the block, apparatus, system, technique, or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuitry or logic, general purpose hardware or controller, or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, that are executed on a device on a target real or virtual processor, to carry out the methods 500 and 600 described above with reference to Figures 2-6. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined into, or divided among, program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located on both local storage media and remote storage media.

Program code for carrying out the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a universal computer, specialized computer, or other programmable data processing apparatus such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may be executed entirely on one machine, partially on the machine as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on the remote machine or on a server.

In the context of the present disclosure, the computer program codes or related data may be carried by any suitable medium to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of a medium include a signal, computer-readable medium and the like.

The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer-readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk drive, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM, or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Furthermore, although the operations are depicted in a particular order, it should not be construed as requiring that such operations be performed in the particular order shown or in sequential order, or that all operations illustrated be performed, to achieve desirable results. Multitasking and parallel processing may be advantageous in certain circumstances. Likewise, although the foregoing discussions contain various specific implementation details, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of independent embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the present disclosure has been described in specific languages for structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are described as illustrative ways of implementing the claims.

Claims (15)

1. A first device (110), comprising: means for receiving at least one transport block from a second device (120) in a predetermined bandwidth portion for transmission to the first device (110), the at least one transport block being transmitted in a set of subbands of the predetermined bandwidth portion; means for generating at least one feedback based on a set of reception states of the at least one transport block in the set of subbands; and means for transmitting the at least one feedback to the second device (120) wherein the at least one feedback is configured to cause the second device to adjust a contention window size for further transmission from the second device to the first device (110), wherein the at least one feedback is configured to reset the contention window size for a subband in the set of subbands for successful reception of the at least one transport block in the subband of the set of subbands and to increase the contention window size for unsuccessful reception of the at least one transport block in the subband of the set of subbands. 2. The first device (110) of claim 1, wherein the first device (110) further comprises means for determining at least one reference time interval in the predetermined bandwidth portion for transmission; means for determining whether the at least one transport block is received in the at least one reference time interval; and means for generating the at least one feedback in response to determining a receipt of the at least one transport block in the at least one reference time interval. 3. The first device (110) of claim 2, further comprising means for receiving, from the second device, an indication of the at least one reference time interval; and means for determining the at least one reference time interval based on the indication. 4. The first device (110) of any of claims 1-3, further comprising means for generating a bit sequence based on the reception states in the set of subbands, each bit indicating whether a reception of the transport block in one of the set of subbands is successful; and means for generating the at least one feedback based on the bit sequence. 5. The first device (110) of claim 4, further comprising means for assigning default values for subbands in the default bandwidth portion in which no transport block is transmitted; and means for generating the bit sequence based on the reception states and default values. 6. The first device (110) of any of claims 1-5, further comprising means for selecting one or more groups of code blocks from the at least one transport block transmitted in a same subband in at least one reference time interval; means for determining a successful reception rate of the one or more groups of selected code blocks; and means for determining successful reception of the at least one transport block in response to determining that the successful reception rate exceeds a threshold reception rate. 7. The first device (110) of any one of claims 1-6, wherein the at least one feedback is transmitted together with a response for receiving the at least one transport block from the second device to the first device. 8. The first device (110) of claim 7, wherein the response comprises a hybrid auto-repeat request confirmation of the at least one transport block. 9. The first device (110) of any of claims 1-8, further comprising means for receiving from the second device an indication of a configured timing for the at least one feedback; and transmit at least one feedback on timing based on the indication. 10. The first device (110) of claim 9, wherein the timing configured for the feedback is a timing for a hybrid auto-repeat request acknowledgement corresponding to the at least one transport block. 11. The first device (110) of claim 1, further comprising means for determining the set of reception states of the at least one transport block in the set of subbands; means for determining successful reception of the at least one transport block in a subband of the set of subbands in response to a certain percentage of code blocks or groups of code blocks being successfully received. 12. A second device (120) comprising: means for transmitting at least one transport block to a first device (110) in a predetermined bandwidth portion for a transmission from the second device, the at least one transport block being transmitted in a set of subbands of the predetermined bandwidth portion; means for receiving at least one feedback from the first device, the at least one feedback being generated based on a set of reception states of the at least one transport block in the set of subbands; means for adjusting at least one contention window size for further transmission from the second device to the first device based on the at least one feedback; means for determining the set of reception states of the at least one transport block in the set of subbands from the at least one feedback; means for resetting the at least one contention window size for a subband in response to determining successful reception of the at least one transport block in the subband of the set of subbands; and means for increasing the at least one contention window size for the subband in response to determining a failed reception of the at least one transport block in the subband of the set of subbands. 13. A method comprising: transmitting (610) at least one transport block to a first device (110) in a predetermined bandwidth portion for transmission from a second device (120) to the first device (110), transmitting the at least one transport block in a set of subbands of the predetermined bandwidth portion; receiving (620) feedback from the first device (110), the feedback generated based on a set of reception states of the at least one transport block in the set of subbands; adjusting (630) a contention window size for further transmission from the second device (120) to the first device (110) based on the feedback; determining the set of reception states of the at least one transport block in the set of subbands from the feedback; in response to determining a successful reception of the at least one transport block in a first subband of the subband set, resetting the contention window size for the first subband; and in response to determining a failed reception of the at least one transport block in a second subband of the subband set, increasing the contention window size for the second subband. 14. A method comprising: receiving by a first device (110) at least one transport block from a second device (120) in a predetermined bandwidth portion for transmission to the first device (110), the at least one transport block being transmitted in a set of subbands of the predetermined bandwidth portion; generating by the first device (110) at least one feedback based on a set of reception states of the at least one transport block in the set of subbands; and transmitting by the first device (110) the at least one feedback to the second device (120), wherein the at least one feedback is configured to cause the second device (120) to adjust a contention window size for further transmission from the second device (120) to the first device (110), the at least one feedback is configured to reset the contention window size for a subband in the set of subbands for successful reception of the at least one transport block in the subband of the set of subbands and to increase the contention window size for unsuccessful reception of the at least one transport block in the subband of the set of subbands. 15. The method of claim 14, further comprising determining by the first device (110) the set of reception states of the at least one transport block in the set of subbands; determining by the first device (110) a successful reception of the at least one transport block in a subband of the set of subbands in response to a certain percentage of code blocks or groups of code blocks being successfully received.